全文获取类型
收费全文 | 987篇 |
免费 | 146篇 |
国内免费 | 92篇 |
专业分类
电工技术 | 13篇 |
综合类 | 45篇 |
化学工业 | 186篇 |
金属工艺 | 18篇 |
机械仪表 | 56篇 |
建筑科学 | 28篇 |
矿业工程 | 8篇 |
能源动力 | 50篇 |
轻工业 | 171篇 |
水利工程 | 8篇 |
石油天然气 | 5篇 |
武器工业 | 2篇 |
无线电 | 117篇 |
一般工业技术 | 76篇 |
冶金工业 | 16篇 |
原子能技术 | 4篇 |
自动化技术 | 422篇 |
出版年
2024年 | 2篇 |
2023年 | 30篇 |
2022年 | 22篇 |
2021年 | 36篇 |
2020年 | 28篇 |
2019年 | 31篇 |
2018年 | 30篇 |
2017年 | 36篇 |
2016年 | 49篇 |
2015年 | 46篇 |
2014年 | 40篇 |
2013年 | 65篇 |
2012年 | 123篇 |
2011年 | 98篇 |
2010年 | 116篇 |
2009年 | 147篇 |
2008年 | 82篇 |
2007年 | 99篇 |
2006年 | 71篇 |
2005年 | 37篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1994年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有1225条查询结果,搜索用时 15 毫秒
71.
Shu Y. Sun Wen G. Jiang Yu P. Zhao 《International Journal of Food Science & Technology》2012,47(1):100-106
To compare the influence of cultivars on the production of aroma compounds and polyphenols, eight cherry varieties (six sweet and two sour) were fermented into cherry wines, and their compositions were analysed. Results showed that by headspace solid microextraction coupled to gas chromatography–mass spectrometry (HS‐SPME‐GC‐MS), a total of twenty‐first aromatic compounds, mostly consisting of esters, acids, terpenoids and C13‐norisoprenoids, were identified, and eleven polyphenols including five anthocyanins and six phenolic acids were quantified using HPLC. May Duck and Early Richmond wines contained significantly higher levels of phenolic acids (>42 mg L?1) that were associated with high contents of chlorogenic and neochlorogenic acids and also relatively high amounts of octanoic acid and β‐damascenone (odour activity values ≥1000). Hongdeng, Zhifuhong and Bing wines were characterised by higher concentrations of anthocyanins (>41 mg L?1) and also relatively higher levels of isopentyl acetate. Lapins and Governer Wcod wines were distinguished by lower concentrations of polyphenols and relatively higher contents of ethyl 3‐methylbutanoate. 相似文献
72.
73.
《Food Control》2015
Chinese red pepper (Zanthoxylum bungeanum Maxim.) leaf (ZML) extract contains high amounts of phenolic compounds possessing high total antioxidant capacity and hydroxyl, 1, 1-dipheny-2-picrylhydrazyl (DPPH) free radical scavenging activity. ZML extract was investigated as a natural antioxidant for the lipid stability of salted silver carp (Hypophthalmichthys molitrix) throughout salting and drying. Both dorsal and ventral muscles were examined for differences in moisture content, salt content, total lipid content, and degree of lipid oxidation. The hexanal content, Thiobarbituric acid reactive substances (TBARS) value, and lipoxygenase (LOX) activity in the ventral muscle were significantly higher than those of the dorsal muscle (p < 0.05). In the treatments with ZML extract, the hexanal content, the TBARS value, and the LOX activity were significantly lower (p < 0.05) during processing both in the dorsal and ventral muscles. The sensory qualities of processed salted fish could be improved with the amount of 0.030% extract in the dorsal muscle and 0.045% extract in the ventral muscle. These results showed that ZML extract can be a source of natural antioxidants and used as a food additive. 相似文献
74.
采用改进剑桥弹塑性动力本构模型,考虑了结构与地基之间的界面接触效应,对循环波压力作用下软土地基与大圆筒结构物耦合系统进行了弹塑性有限元分析。 相似文献
75.
《Catalysis communications》2011,14(1):101-105
Well-ordered hexagonal mesoporous silicate (HMS) materials with various contents of phosphotungstic acid (HPW) were synthesized via an original direct synthesis method. The characterization results show that the samples have regular fingerprint-like mesopores and spherical morphology. Compared with the conventional wet impregnation method, the samples obtained by the original direct synthesis method have better HPW dispersion and larger specific surface area. Finally, the catalytic performance of these samples was tested through the oxidative desulfurization (ODS) of DBT in the model oil. The results indicate that the direct synthesized samples exhibit better catalytic performance than the impregnated samples. 相似文献
76.
This paper is concerned with the leader-following consensus problem of a group of au-tonomous agents with unknown parameters and unmodeled bounded additive disturbances. Under the assumption that the topology graph has symmetric weights, distributed adaptive controllers are proposed to guarantee that each agent can follow the leader in the presence of bounded disturbances. For the dynamics without disturbances, the proposed dynamic controller ensures that the states of all agents track the leader’s state, and the errors of parameters eventually converge to the compact set which can be made as small as desired by an appropriate choice of the design parameters. 相似文献
77.
Shu Yang Sun Han Sheng Gong Kun Zhao Xiao Lin Wang Xue Wang Xi Hao Zhao Bing Yu Huan Xin Wang 《International Journal of Food Science & Technology》2013,48(9):1783-1790
This study examined the effect of co‐inoculation of yeast and lactic acid bacteria (LAB) on the chemical and sensory characteristics of cherry wines, in comparison with a traditional sequential culture. Three LABs were investigated, including two O. oeni (SG26 and Viniflora) and one L. plantarum (PL18). All co‐inoculations significantly shortened the fermentation time (average 8 days earlier) to reach a stable level of residual sugar (<2 g L?1) and L‐malic acid (<0.5 g L?1), and no inhibitory effect on the yeast proliferation was observed. For volatiles determined, co‐culture with SG26 produced the greatest amount of volatile components (138.5 mg L?1), whereas sequential inoculation with PL18 had the lowest level (119.6 mg L?1). PCA result revealed that different LABs had diverse influences on the volatile profile of cherry wines, and sensory analysis confirmed that these samples presented distinct sensory profiles, and particularly, a stronger note of fruity was perceived when co‐culture was used. 相似文献
78.
79.
模糊数据挖掘在电子政务中的应用 总被引:1,自引:0,他引:1
文章首先介绍了数据挖掘技术和模糊数据挖掘技术,然后给出了模糊数据挖掘算法以及详细的模糊数据挖掘步骤,最后用一个具体实例证明了模糊数据挖掘在电子政务系统中的应用价值。 相似文献
80.